Many analytical and preparative methods used in biology and medicine are based on binding molecules of interest that are contained in a biological sample to ligands attached to a substrate.
Generally, the ligands are biomolecules (e.g., polypeptides or nucleic acids), cells, or drugs. The substrate is a support made of plastics, glass, silicon, fiber, or cellulose. A ligand can be stably attached to a substrate surface, either by covalent bonding or non-covalent interaction.
A large number of different ligands can be attached to a substrate to generate a ligand array. Such an array allows simultaneous analyses of different types of molecules in a biological sample through binding the molecules to specific ligands within the array. There are many important applications of ligand arrays, including drug discovery and diagnostic medicine. See, e.g., U.S. Pat. No. 6,171,797B1.